JP2019090043A - Polycarbonate resin composition for optical component, and optical component - Google Patents

Abstract

To provide a polycarbonate resin composition for an optical component which is excellent in transparency and thermal discoloration resistance, and to provide an optical component.SOLUTION: The polycarbonate resin composition for an optical component contains 0.1-4 pts.mass of a polyalkylene glycol (B) and 0.005-0.5 pt.mass of a phosphorus-based stabilizer (C) based on 100 pts.mass of a polycarbonate resin (A). The polyalkylene glycol (B) contains a copolymerization component obtained by copolymerizing two or more units selected from a tetramethylene glycol unit (b1), a (2-methyl)ethylene glycol unit (b2), and an ethylene glycol unit (b3). The phosphorus-based stabilizer (C) contains a phosphite-based stabilizer (C-I) represented by a specific formula (I) and/or a phosphite-based stabilizer (C-II) represented by a specific formula (II).SELECTED DRAWING: None

Description

  The present invention relates to a polycarbonate resin composition for an optical component and an optical component, and more particularly, to a polycarbonate resin composition for an optical component which is excellent in transparency and heat-resistant discoloration and an optical component obtained by molding the same.

  A planar light source device is incorporated in a liquid crystal display device used for a personal computer, a cellular phone or the like in order to meet the demand for thinning, weight saving, labor saving and high definition. The planar light source device has a wedge-shaped light guide plate or a flat plate shape having a uniform inclined surface for the purpose of guiding the incoming light uniformly and efficiently to the liquid crystal display side. A light guide plate is provided.

  Such a light guide plate is obtained by injection molding of a thermoplastic resin, and the above-mentioned concavo-convex pattern is imparted by transfer of the concavo-convex portion formed on the surface of the nest. Conventionally, the light guide plate has been molded from a resin material such as polymethyl methacrylate (PMMA), but recently, a display device for projecting a clearer image is required, and the heat generated in the vicinity of the light source raises the temperature inside the device It is being replaced by polycarbonate resin materials with higher heat resistance.

  A polycarbonate resin is excellent in mechanical properties, thermal properties, electrical properties, and weather resistance, but its transparency is lower than PMMA etc., so a surface light source is obtained from a light guide plate made of polycarbonate resin and a light source. When configured, there is a problem that the brightness is low. In recent years, it has been required to reduce the difference in chromaticity between the light entrance portion of the light guide plate and a location away from the light entrance portion, but polycarbonate resins have a problem of being easily yellowed as compared with PMMA resins.

  Recently, in various types of mobile terminals such as smartphones and tablet terminals, thinning and large-scale thinning have progressed at a remarkable speed, and edge type is used in which light is incident on the light guide plate from the direct type to the side edge Even if the optical path length is long as an ultra-thin light source, sufficient luminance is required. In such a high-end light guide plate, at present, it is difficult to satisfy the required specifications at the transparency and the yellowing resistance level achieved by the above-mentioned conventional techniques.

  The inventor of the present invention, in Patent Document 1, proposed a polycarbonate resin composition using a polyalkylene glycol copolymer having a specific alkylene glycol unit. The composition is an excellent material capable of achieving high light transmittance and good hue, but it has been found that the heat discoloration resistance has some drawbacks.

JP, 2016-130298, A

  The present invention has been made in view of the above-mentioned circumstances, and an object (problem) of the present invention is to provide a polycarbonate resin composition for optical parts which is excellent in transparency and heat discoloration resistance without impairing the original characteristics of polycarbonate resin. It is.

As a result of intensive studies to achieve the above-mentioned problems, the present inventor is transparent by blending a copolymerized polyalkylene glycol having a specific alkylene glycol unit and a specific phosphorus-based stabilizer in a specific amount. It has been found that a polycarbonate resin composition having excellent properties and heat discoloration resistance can be obtained, and the present invention has been completed.
The present invention relates to the following optical components of the polycarbonate resin composition for optical components.

[1] A resin composition containing 0.1 to 4 parts by mass of a polyalkylene glycol (B) and 0.005 to 0.5 parts by mass of a phosphorus-based stabilizer (C) with respect to 100 parts by mass of a polycarbonate resin (A) The object,
A copolymer component in which polyalkylene glycol (B) is copolymerized with at least two or more units selected from tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) Including
A phosphite stabilizer (C-I) represented by the following general formula (I) and / or a phosphite stabilizer (C-) represented by the following general formula (II) Polycarbonate resin composition for optical parts characterized by including II).
(In formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represent an alkyl group, an aryl group or an aralkyl group, and a to d respectively independently shows the integer of 0-3.)
(In formula (II), R ^{21 to} R ²⁵ each independently represent a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.

[2] A copolymer in which (2-methyl) ethylene glycol unit (b2) and / or ethylene glycol unit (b3) in polyalkylene glycol (B) is copolymerized with tetramethylene glycol unit (b1) The polycarbonate resin composition for optical parts as described in [1].
[3] The above-mentioned [1] which is a copolymer in which (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) in polyalkylene glycol (B) are copolymerized with tetramethylene glycol unit (b1) ] Or the polycarbonate resin composition for optical components as described in [2].
[4] Polyalkylene glycol (B) is
(I) A copolymer having tetramethylene glycol unit (b1) and (2-methyl) ethylene glycol unit (b2),
(Ii) Copolymer having tetramethylene glycol unit (b1) and ethylene glycol unit (b3), or (iii) Copolymer having (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) Or a combination of two or more copolymers selected from
(Iv) It is contained as a copolymer having tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3). The polycarbonate resin composition for optical parts in any one of these.

[5] A polyalkylene glycol (B) is contained by using the copolymer of (i) and the copolymer of (ii) in combination, or is contained as a copolymer of (iv) The polycarbonate resin composition for optical parts as described in said [4].
[6] The aromatic polycarbonate resin according to any one of the above [1] to [5], wherein the phosphite stabilizer (CI) is a compound represented by the following structural formula (Ia) Composition.
[7] The polycarbonate resin composition for optical parts according to any one of the above [1] to [6], wherein the number average molecular weight of the polyalkylene glycol (B) is more than 1,200 to less than 5,000.
[8] The polycarbonate resin composition according to any one of the above [1] to [7], which further contains an epoxy compound (D) or an oxetane compound (E).
[9] An optical component obtained by molding the polycarbonate resin composition according to any one of the above [1] to [8].

  The polycarbonate resin composition for an optical component of the present invention is excellent in transparency and heat-resistant color-changing property, and therefore, can be suitably used for various optical components, particularly thin optical components.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples.
The polycarbonate resin composition for optical parts of the present invention comprises 0.1 to 4 parts by mass of polyalkylene glycol (B) and 0.005 to phosphorus stabilizer (C) per 100 parts by mass of polycarbonate resin (A). A resin composition containing 0.5 parts by mass of
A copolymer component in which polyalkylene glycol (B) is copolymerized with at least two or more units selected from tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) Including
Phosphate-based stabilizers (C-I) represented by the above general formula (I) and / or phosphite-based stabilizers (C-based) represented by the above general formula (II) And II).

[Polycarbonate resin (A)]
There is no restriction on the type of polycarbonate resin used in the present invention, and one type of polycarbonate resin may be used, or two or more types may be used in combination in an arbitrary ratio and an arbitrary ratio.
The polycarbonate resin is a polymer of a basic structure having a carbonic acid bond represented by the formula:-[-O-X-O-C (= O)-]-.
In the formula, X is generally a hydrocarbon, but a hetero atom or X having a hetero bond may be used for various properties.

  Further, polycarbonate resins can be classified into aromatic polycarbonate resins in which carbon directly bonded to carbonic bonds is aromatic carbon and aliphatic polycarbonate resins in which aliphatic carbon is directly bonded, but any of them can be used. Among them, aromatic polycarbonate resins are preferable from the viewpoint of heat resistance, mechanical physical properties, electrical characteristics and the like.

  Although there is no restriction | limiting in the specific kind of polycarbonate resin, For example, the polycarbonate polymer which makes a dihydroxy compound and a carbonate precursor react is mentioned. At this time, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Alternatively, carbon dioxide may be reacted with cyclic ether as a carbonate precursor. The polycarbonate polymer may be linear or branched. Furthermore, the polycarbonate polymer may be a homopolymer comprising one kind of repeating unit, or may be a copolymer having two or more kinds of repeating units. At this time, as the copolymer, various copolymer forms such as a random copolymer and a block copolymer can be selected. In general, such polycarbonate polymers are thermoplastic resins.

  Among the monomers used as the raw material of the aromatic polycarbonate resin, to cite an example of the aromatic dihydroxy compound,

Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (that is, resorcinol), 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl;

2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1 , Dihydroxynaphthalenes such as 7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene;

2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis (3-hydroxyphenoxy) Dihydroxy diaryl ethers such as benzene and 1,3-bis (4-hydroxyphenoxy) benzene;

2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A),
1,1-bis (4-hydroxyphenyl) propane,
2,2-bis (3-methyl-4-hydroxyphenyl) propane,
2,2-bis (3-methoxy-4-hydroxyphenyl) propane,
2- (4-hydroxyphenyl) -2- (3-methoxy-4-hydroxyphenyl) propane,
1,1-bis (3-tert-butyl-4-hydroxyphenyl) propane,
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane,
2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane,
2- (4-hydroxyphenyl) -2- (3-cyclohexyl-4-hydroxyphenyl) propane,
α, α'-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene,
1,3-bis [2- (4-hydroxyphenyl) -2-propyl] benzene,
Bis (4-hydroxyphenyl) methane,
Bis (4-hydroxyphenyl) cyclohexylmethane,
Bis (4-hydroxyphenyl) phenylmethane,
Bis (4-hydroxyphenyl) (4-propenylphenyl) methane,
Bis (4-hydroxyphenyl) diphenylmethane,
Bis (4-hydroxyphenyl) naphthylmethane,
1,1-bis (4-hydroxyphenyl) ethane,
1,1-bis (4-hydroxyphenyl) -1-phenylethane,
1,1-bis (4-hydroxyphenyl) -1-naphthyl ethane,
1,1-bis (4-hydroxyphenyl) butane,
2,2-bis (4-hydroxyphenyl) butane,
2,2-bis (4-hydroxyphenyl) pentane,
1,1-bis (4-hydroxyphenyl) hexane,
2,2-bis (4-hydroxyphenyl) hexane,
1,1-bis (4-hydroxyphenyl) octane,
2,2-bis (4-hydroxyphenyl) octane,
4,4-bis (4-hydroxyphenyl) heptane,
2,2-bis (4-hydroxyphenyl) nonane,
1,1-bis (4-hydroxyphenyl) decane,
1,1-bis (4-hydroxyphenyl) dodecane,
Etc. bis (hydroxyaryl) alkanes such as

1,1-bis (4-hydroxyphenyl) cyclopentane,
1,1-bis (4-hydroxyphenyl) cyclohexane,
1,1-bis (4-hydroxyphenyl) -3,3-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,4-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,5-dimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane,
1,1-bis (4-hydroxy-3,5-dimethylphenyl) -3,3,5-trimethylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3-propyl-5-methylcyclohexane,
1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane,
1,1-bis (4-hydroxyphenyl) -4-tert-butyl-cyclohexane,
1,1-bis (4-hydroxyphenyl) -3-phenylcyclohexane,
1,1-bis (4-hydroxyphenyl) -4-phenylcyclohexane,
Etc. bis (hydroxyaryl) cycloalkanes;

9,9-bis (4-hydroxyphenyl) fluorene,
Cardo-structure-containing bisphenols such as 9,9-bis (4-hydroxy-3-methylphenyl) fluorene;

4,4'-dihydroxydiphenyl sulfide,
Dihydroxy diaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide;

Dihydroxy diaryl sulfoxides such as 4,4'-dihydroxy diphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfoxide;

4,4'-dihydroxydiphenyl sulfone,
Dihydroxy diaryl sulfones such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfone;
Etc.

Among these, bis (hydroxyaryl) alkanes are preferable, and in particular, bis (4-hydroxyphenyl) alkanes are preferable, and in particular, in view of impact resistance and heat resistance, 2,2-bis (4-hydroxyphenyl) propane ( That is, bisphenol A) is preferred.
In addition, 1 type may be used for an aromatic dihydroxy compound, and 2 or more types may be used together by arbitrary combinations and a ratio.

In addition, as an example of a monomer that is a raw material of aliphatic polycarbonate resin,
Ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3- Alkane diols such as diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol and decane-1,10-diol;

  Cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, 2,2,4,4, Cycloalkane diols such as 4-tetramethyl-cyclobutane-1,3-diol;

  Glycols such as ethylene glycol, 2,2'-oxydiethanol (ie, diethylene glycol), triethylene glycol, propylene glycol, spiro glycol and the like;

  1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis ( 2-hydroxyethoxy) benzene, 2,3-bis (hydroxymethyl) naphthalene, 1,6-bis (hydroxyethoxy) naphthalene, 4,4'-biphenyldimethanol, 4,4'-biphenyldiethanol, 1,4- Aralkyl diols such as bis (2-hydroxyethoxy) biphenyl, bisphenol A bis (2-hydroxyethyl) ether, bisphenol S bis (2-hydroxyethyl) ether;

  1,2-epoxyethane (ie ethylene oxide), 1,2-epoxypropane (ie propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4-epoxycyclohexane, 1-methyl -Cyclic ethers such as 1,2-epoxycyclohexane, 2,3-epoxy norbornane, and 1,3-epoxypropane; and the like.

  Among the monomers used as the raw materials of polycarbonate resins, carbonyl halides, carbonate esters and the like are used as examples of carbonate precursors. In addition, 1 type may be used for a carbonate precursor and it may use 2 or more types together by arbitrary combinations and a ratio.

  Specific examples of the carbonyl halide include phosgene; bischloroformates of dihydroxy compounds, haloformates such as monochloroformates of dihydroxy compounds, and the like.

  Specific examples of the carbonate ester include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds; monocarbonates of dihydroxy compounds; cyclic carbonates And carbonates of dihydroxy compounds such as

Method for Producing Polycarbonate Resin The method for producing polycarbonate resin is not particularly limited, and any method can be adopted. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring opening polymerization method of a cyclic carbonate compound, and a solid phase transesterification method of a prepolymer.
Among these methods, particularly preferred ones will be specifically described below.

Interfacial Polymerization Method First, the case of producing a polycarbonate resin by an interfacial polymerization method will be described.
In the interfacial polymerization method, after the dihydroxy compound is reacted with a carbonate precursor (preferably phosgene) in the presence of an organic solvent inert to the reaction and an alkaline aqueous solution, the pH is usually maintained at 9 or more. The polycarbonate resin is obtained by performing interfacial polymerization in the presence. In addition, in the reaction system, a molecular weight modifier (end stopper) may be present if necessary, and an antioxidant may be present to prevent oxidation of the dihydroxy compound.

  The dihydroxy compound and the carbonate precursor are as described above. Among the carbonate precursors, it is preferable to use phosgene, and a method using phosgene is particularly called phosgene method.

  Examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene, and dichlorobenzene; and aromatic hydrocarbons such as benzene, toluene, and xylene; Be In addition, an organic solvent may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  Examples of the alkali compound contained in the aqueous alkali solution include alkali metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium hydrogencarbonate and alkaline earth metal compounds, among which sodium hydroxide and water Potassium oxide is preferred. In addition, an alkali compound may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  Although the concentration of the alkali compound in the aqueous alkali solution is not limited, it is usually used at 5 to 10% by mass in order to control the pH in the aqueous alkali solution of the reaction to 10 to 12. For example, when blowing in phosgene, the molar ratio of the bisphenol compound to the alkali compound is usually 1: 1.9 or more in order to control the pH of the aqueous phase to be 10 to 12, preferably 10 to 11. It is preferable to set it as 1: 2.0 or more, usually 1: 3.2 or less, and in particular 1: 2.5 or less.

  Examples of the polymerization catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine and trihexylamine; and alicyclic resins such as N, N'-dimethylcyclohexylamine and N, N'-diethylcyclohexylamine Aromatic amines such as tertiary amines; N, N'-dimethylaniline, N, N'-diethylaniline; quaternary ammonium salts such as trimethylbenzyl ammonium chloride, tetramethyl ammonium chloride, triethyl benzyl ammonium chloride, etc. Pyridine; salts of guanidine; and the like. The polymerization catalyst may be used alone, or two or more may be used in any combination and ratio.

  Examples of the molecular weight modifier include aromatic phenols having a monohydric phenolic hydroxyl group; aliphatic alcohols such as methanol and butanol; mercaptan; phthalimide and the like, among which aromatic phenols are preferable. Specific examples of such aromatic phenols include alkyl groups such as m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenols. Examples thereof include substituted phenols; vinyl group-containing phenols such as isopropenyl phenol; epoxy group-containing phenols; carboxyl group-containing phenols such as o-hydroxybenzoic acid and 2-methyl-6-hydroxyphenylacetic acid; In addition, a molecular weight modifier may be used 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the molecular weight modifier used is usually 0.5 mol or more, preferably 1 mol or more, and usually 50 mol or less, preferably 30 mol or less, per 100 mol of the dihydroxy compound. By making the usage-amount of a molecular weight modifier into this range, the thermal stability and hydrolysis resistance of a resin composition can be improved.

In the reaction, the order of mixing the reaction substrate, reaction medium, catalyst, additive and the like is arbitrary as long as a desired polycarbonate resin can be obtained, and the appropriate order may be arbitrarily set. For example, when phosgene is used as the carbonate precursor, the molecular weight modifier can be mixed at any time between the time of the reaction between the dihydroxy compound and phosgene (phosgenation) and the time of the polymerization reaction start.
The reaction temperature is usually 0 to 40 ° C., and the reaction time is usually several minutes (eg, 10 minutes) to several hours (eg, 6 hours).

Melt Transesterification Method Next, the case of producing a polycarbonate resin by a melt transesterification method will be described.
In the melt transesterification method, for example, a transesterification reaction of carbonic acid diester with a dihydroxy compound is performed.

The dihydroxy compound is as described above.
On the other hand, as a carbonic diester, for example, dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate, di-tert-butyl carbonate and the like; diphenyl carbonate; substituted diphenyl carbonates such as ditolyl carbonate and the like can be mentioned. Among them, diphenyl carbonate and substituted diphenyl carbonate are preferable, and particularly diphenyl carbonate is more preferable. One carbonic diester may be used, or two or more carbonic diesters may be used in any combination and ratio.

  The ratio between the dihydroxy compound and the carbonic diester is arbitrary as long as the desired polycarbonate resin can be obtained, but it is preferable to use an equal molar amount or more of the carbonic diester with respect to 1 mol of the dihydroxy compound. Is more preferred. The upper limit is usually 1.30 moles or less. By setting it as such a range, the amount of terminal hydroxyl groups can be adjusted to a suitable range.

  In polycarbonate resins, the amount of terminal hydroxyl groups tends to greatly affect the thermal stability, hydrolysis stability, color tone and the like. Therefore, the amount of terminal hydroxyl groups may be adjusted as necessary by any known method. In the transesterification reaction, a polycarbonate resin in which the amount of terminal hydroxyl groups is adjusted can usually be obtained by adjusting the mixing ratio of the carbonic diester and the aromatic dihydroxy compound; the degree of pressure reduction at the time of the transesterification reaction. In addition, the molecular weight of the polycarbonate resin usually obtained can also be adjusted by this operation.

When adjusting the mixing ratio of carbonic diester and dihydroxy compound to adjust the amount of terminal hydroxyl groups, the mixing ratio is as described above.
Further, as a more positive adjustment method, a method of mixing an end terminator separately at the time of reaction may be mentioned. Examples of the terminal stopper at this time include monohydric phenols, monohydric carboxylic acids, carbonic diesters and the like. In addition, 1 type may be used for end terminator and 2 or more types may be used together by arbitrary combinations and a ratio.

  In the production of a polycarbonate resin by a melt transesterification method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among them, it is preferable to use, for example, an alkali metal compound and / or an alkaline earth metal compound. In addition, for example, basic compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds and amine compounds may be used in combination. In addition, 1 type may be used for a transesterification catalyst, and 2 or more types may be used together by arbitrary combinations and a ratio.

  In the melt transesterification method, the reaction temperature is usually 100 to 320 ° C. Moreover, the pressure at the time of reaction is usually a reduced pressure condition of 2 mmHg or less. As a specific operation, a melt polycondensation reaction may be carried out while removing by-products such as aromatic hydroxy compounds under the above conditions.

  The melt polycondensation reaction can be carried out either batchwise or continuously. When carrying out by a batch system, the order which mixes a reaction substrate, a reaction medium, a catalyst, an additive etc. is arbitrary as long as a desired aromatic polycarbonate resin is obtained, and what is necessary is just to set an appropriate order arbitrarily. However, in consideration of the stability of the polycarbonate resin, it is preferable to carry out the melt polycondensation reaction continuously.

  In the melt transesterification method, if necessary, a catalyst deactivator may be used. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be optionally used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. The catalyst deactivator may be used alone or in combination of two or more at any ratio and ratio.

  The amount of catalyst deactivator used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, with respect to the alkali metal or alkaline earth metal contained in the above-mentioned transesterification catalyst. Preferably, it is 5 equivalents or less. Furthermore, it is usually 1 ppm or more, and usually 100 ppm or less, preferably 20 ppm or less, relative to the polycarbonate resin.

The molecular weight of the polycarbonate resin (A) is preferably 10,000 to 15,000 by viscosity average molecular weight (Mv) converted from solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. Preferably, it is 10,500 or more, more preferably 11,000 or more, in particular 11,500 or more, most preferably 12,000 or more, and more preferably 14,500 or less. By setting the viscosity average molecular weight to the lower limit value or more of the above range, the mechanical strength of the polycarbonate resin composition for optical parts of the present invention can be further improved, and the viscosity average molecular weight to be below the upper limit value of the above range Thus, the flowability of the polycarbonate resin composition for optical parts of the present invention can be suppressed and improved, and the molding processability can be enhanced to facilitate thin-wall molding.
In addition, you may mix and use 2 or more types of polycarbonate resin from which a viscosity average molecular weight differs, and in this case, you may mix the polycarbonate resin whose viscosity average molecular weight is out of said preferable range.

In addition, with viscosity average molecular weight [Mv], using methylene chloride as a solvent, the intrinsic viscosity [ロ ー] (unit dl / g) at a temperature of 25 ° C. is determined using a Ubbelohde viscometer, and Schnell's viscosity formula, ie, , = 1 = 1.23 × 10 ⁻⁴ Mv ^0.83 . In addition, the intrinsic viscosity [η] is a value calculated by measuring the specific viscosity [で_sp ] at each solution concentration [C] (g / dl) according to the following equation.

  The terminal hydroxyl group concentration of the polycarbonate resin is arbitrary and may be appropriately selected and determined, but is usually 1000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less. This can further improve the retention heat stability and color tone of the polycarbonate resin. The lower limit is usually 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more, particularly for polycarbonate resins produced by the melt transesterification method. Thereby, the fall of molecular weight can be suppressed and the mechanical property of a resin composition can be improved more.

  In addition, the unit of terminal hydroxyl group concentration represents the mass of terminal hydroxyl group to ppm with respect to the mass of polycarbonate resin. The measurement method is the colorimetric determination by the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

  Polycarbonate resin is not limited to an embodiment including polycarbonate resin alone (polycarbonate resin alone is not limited to one including only one kind of polycarbonate resin, for example, it is used in a sense including an embodiment including plural kinds of polycarbonate resins different in monomer composition and molecular weight from each other) And may be used in combination with alloys (mixtures) of polycarbonate resins and other thermoplastic resins. Furthermore, for example, in order to further enhance flame retardancy and impact resistance, polycarbonate resin is copolymerized with an oligomer or polymer having a siloxane structure; phosphorus atom for the purpose of further enhancing thermal oxidation stability and flame retardancy Copolymers with monomers, oligomers or polymers having the formula; Copolymers with monomers, oligomers or polymers having the dihydroxyanthraquinone structure for the purpose of improving the thermal oxidation stability; polystyrene etc. to improve the optical properties Copolymer with an oligomer or polymer having an olefin structure; copolymer with a polyester resin oligomer or polymer for the purpose of improving chemical resistance; or even a copolymer based on a polycarbonate resin Good.

  The polycarbonate resin may contain a polycarbonate oligomer in order to improve the appearance and fluidity of the molded article. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9000 or less. Furthermore, the content of the polycarbonate oligomer is preferably 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Furthermore, the polycarbonate resin may be not only a virgin raw material but also a polycarbonate resin regenerated from a used product (so-called material recycled polycarbonate resin).
However, it is preferable that it is 80 mass% or less among polycarbonate resin, and it is more preferable that it is 50 mass% or less among regenerated polycarbonate resin. Since the recycled polycarbonate resin is highly likely to be degraded due to thermal degradation, aging degradation, etc., when such polycarbonate resin is used more than the above range, it is possible to lower the hue and mechanical properties. It is because there is sex.

[Polyalkylene glycol (B)]
The polycarbonate resin composition for optical parts of the present invention copolymerizes at least two or more units selected from tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) It contains a copolymerization component.
In the present specification, a unit means alkylene such as tetramethylene ether unit, (2-methyl) ethylene ether unit and ethylene ether unit derived from tetramethylene glycol, (2-methyl) ethylene glycol and ethylene glycol etc. An alkylene ether unit such as an ether unit is meant. The terminal group of the polyalkylene glycol may be a hydroxyl group linked to these units, or a substituent as described later.
When the polyalkylene glycol (A) is a mixture of polyalkylene glycols, it means a constituent unit of each polyalkylene glycol, or when the polyalkylene glycol (A) is a copolymer, a constituent unit thereof.

  And it is preferable that the said (b1), (b2) and (b3) which polyalkylene glycol (B) contains as a copolymer which copolymerized at least 2 or more unit chosen from these. In addition, in polyalkylene glycol (B), (2-methyl) ethylene glycol unit (b2) and / or ethylene glycol unit (b3) in polyalkylene glycol (B) are copolymerized with tetramethylene glycol unit (b1) Preferred is a copolymer obtained by copolymerizing a copolymer obtained by copolymerizing (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) in polyalkylene glycol (B) with tetramethylene glycol unit (b1). It is preferably a polymer.

As polyalkylene glycol (B), it is preferable to contain the copolymer of the following (i)-(iv).
(I) A copolymer having tetramethylene glycol unit (b1) and (2-methyl) ethylene glycol unit (b2),
(Ii) a copolymer having tetramethylene glycol unit (b1) and ethylene glycol unit (b3),
(Iii) Copolymer having (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3), or
(Iv) It is preferable to contain as a copolymer which has tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2), and ethylene glycol unit (b3).
In the case of (i) to (iii) above, the remaining other alkylene glycol unit is a single polymer thereof or a copolymer with the other remaining unit, or a unit other than (b1) to (b3) And copolymers thereof.

  The polyalkylene glycol (B) is preferably contained in combination of the copolymer of (i) and the copolymer of (ii), or preferably contained as the copolymer of (iv). .

  Methods for producing the polyalkylene glycol copolymers shown in the above (i) to (iv) are well known, and for example, glycols, alkylene oxides or polyether-forming derivatives thereof as described above are generally used as acid catalysts. It can be produced by using and copolymerizing. As a specific manufacturing method, for example, the methods described in JP-A-61-123628 and JP-A-7-224291 can be mentioned.

  Preferred examples of the unit other than (b1) to (b3) include (2-ethyl) ethylene glycol, (2,2'-dimethyl) propylene glycol, (3-methyl) tetramethylene glycol and the like.

In the present invention, as the preferable content of (b1) to (b3) units, the amount of tetramethylene glycol unit (b1) is 0 to 80 mol% based on the total 100 mol% of (b1) to (b3) The amount of (2-methyl) ethylene glycol unit (b2) is 0 to 45 mol%, and the amount of ethylene glycol unit (b3) is 0 to 50 mol%.
As a more preferable content of the (b1) to (b3) units, the amount of tetramethylene glycol unit (b1) in the polyalkylene glycol (B) is based on 100 mol% in total of (b1) to (b3). It is 40 to 80% by mole, the amount of (2-methyl) ethylene glycol unit (b2) is 5 to 45% by mole, and the amount of ethylene glycol unit (b3) is 5 to 50% by mole. The proportion of (b1) to (b3) units is more preferably 45 to 75% by mole, particularly preferably 50 to 70% by mole of (b1), and more preferably 6 to 40% by mole of (b2) The amount is preferably 7 to 35 mol%, and (b3) is more preferably 8 to 45 mol%, particularly preferably 10 to 43 mol%.

The amount of units other than (b1) to (b3) described above is preferably 1 to 10 mol%, more preferably 1 to 5 mol%, based on 100 mol% of the entire polyalkylene glycol (B). It is mol%, More preferably, it is 1 to 3 mol%.
In addition, the measurement of the molar ratio of each unit (b1)-(b3) in polyalkylene glycol (B) is measured using a deuterated chloroform as a solvent, using a < ¹ > H-NMR measuring device.

  Moreover, as for each polyalkylene (co) polymer which comprises a polyalkylene glycol (B), it is preferable that the terminal group is a hydroxyl group. In addition, derivatives whose one end or both ends are capped with alkyl ether, aryl ether, aralkyl ether, fatty acid ester, aryl ester etc. do not affect the performance expression, and etherified or esterified products are used similarly it can.

  As the alkyl group constituting the alkyl ether, either linear or branched may be used, and an alkyl group having 1 to 22 carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, octyl group, lauryl group, Stearyl groups and the like, and methyl ether, ethyl ether, butyl ether, lauryl ether, stearyl ether etc. of polyalkylene glycol can be preferably exemplified.

  The aryl group constituting the aryl ether is preferably an aryl group having preferably 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and still more preferably 6 to 10 carbon atoms, and examples thereof include a phenyl group, a tolyl group and a naphthyl group. And the like, and phenyl group, tolyl group and the like are preferable. The aralkyl group is preferably an aralkyl group having preferably 7 to 23 carbon atoms, more preferably 7 to 13 carbon atoms, and still more preferably 7 to 11 carbon atoms, and examples thereof include a benzyl group and a phenethyl group. Particularly preferred.

The fatty acid constituting the fatty acid ester may be linear or branched, and may be a saturated fatty acid or an unsaturated fatty acid.
The fatty acid constituting the fatty acid ester is a monovalent or divalent fatty acid having 1 to 22 carbon atoms, for example, a monovalent saturated fatty acid such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthate , Caprylic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, monovalent unsaturated fatty acids such as oleic acid, elaidic acid, Unsaturated fatty acids such as linoleic acid, linolenic acid and arachidonic acid, and bivalent fatty acids having 10 or more carbon atoms, such as sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid, tapsialic acid and decenedioic acid, undecene acid Diacid, dodecene diacid.

  The aryl group constituting the aryl ester is preferably an aryl group having preferably 6 to 22 carbon atoms, more preferably 6 to 12 carbon atoms, and still more preferably 6 to 10 carbon atoms, and examples thereof include a phenyl group, a tolyl group and a naphthyl group. And the like, and phenyl group, tolyl group and the like are preferable. The end-capping group exhibits good compatibility with the polycarbonate even if it is an aralkyl group, and thus can exhibit the same action as the aryl group. The aralkyl group preferably has 7 to 23 carbon atoms, more preferably The aralkyl group preferably has 7 to 13 carbon atoms, more preferably 7 to 11 carbon atoms, and examples thereof include a benzyl group and a phenethyl group, with a benzyl group being particularly preferable.

  The polyalkylene glycol (B) may contain, in its structure, a structure derived from a polyol such as 1,4-butanediol, glycerol, sorbitol, benzenediol, bisphenol A, cyclohexanediol, spiroglycol and the like. These organic groups can be provided in the main chain by adding these polyols during the polymerization of polyalkylene glycols. Particularly preferred are glycerol, sorbitol, bisphenol A and the like.

  Examples of polyalkylene glycols containing an organic group in the structure include polyethylene glycol glyceryl ether, poly (2-methyl) ethylene glycol glyceryl ether, poly (2-ethyl) ethylene glycol glyceryl ether, polytetramethylene glycol glyceryl ether, Polyethylene glycol-poly (2-methyl) ethylene glycol glyceryl ether, polytetramethylene glycol-poly (2-methyl) ethylene glycol glyceryl ether, polytetramethylene glycol-poly (2-ethyl) polyethylene glycol glyceryl ether, polyethylene glycol sorbityl Ether, poly (2-methyl) ethylene glycol sorbityl ether, poly (2-ethyl) ethylene glycol sorbitic Ether, polytetramethylene glycol sorbityl ether, polyethylene glycol-poly (2-methyl) ethylene glycol sorbityl ether, polytetramethylene glycol-poly (2-methyl) ethylene glycol sorbityl ether, polytetramethylene glycol-poly (2 -Ethyl) ethylene glycol sorbityl ether, bisphenol A-bis (polyethylene glycol) ether, bisphenol A-bis (poly (2-methyl) ethylene glycol) ether, bisphenol A- bis (poly (2-ethyl) ethylene glycol) Ether, bisphenol A-bis (polytetramethylene glycol) ether, bisphenol A-bis (polyethylene glycol-poly (2-methyl) ethylene glycol) agent And bisphenol A-bis (polytetramethylene glycol-poly (2-methyl) ethylene glycol) ether, bisphenol A-bis (polytetramethylene glycol-poly (2-ethyl) polyethylene glycol) ether and the like. .

The number average molecular weight of the polyalkylene glycol (B) is preferably more than 1,200 to less than 5,000, more preferably more than 1300, still more preferably more than 1400, more preferably less than 4,500, More preferably, it is less than 4,000, particularly preferably 3,500 or less, and most preferably 3,000 or less. If the upper limit of the above range is exceeded, the compatibility is lowered, and this is not preferable.
In addition, in this specification, the number average molecular weight of polyalkylene glycol (B) is defined as a value calculated based on the hydroxyl value measured based on JISK1577.

  The content of the polyalkylene glycol (B) is 0.1 to 4 parts by mass with respect to 100 parts by mass of the polycarbonate resin (A). When the content of the polyalkylene glycol (B) is less than 0.1 parts by mass, the releasability at the time of molding is deteriorated, and when it exceeds 4 parts by mass, the transmittance is reduced due to the white turbidity of the polycarbonate resin. The content of the polyalkylene glycol (B) is preferably 0.15 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 3.5 parts by mass or less, more preferably 3.0 parts by mass or less , Particularly 2.5 parts by mass or less.

[Phosphorus based stabilizer (C)]
The polycarbonate resin composition for optical parts of the present invention contains a phosphorus-based stabilizer (C).
Examples of phosphorus-based stabilizers include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid and polyphosphoric acid; acid pyrophosphate metal salts such as sodium acid pyrophosphate, potassium acid pyrophosphate and calcium acid pyrophosphate; Phosphates of Group 1 or 2 B metals such as potassium phosphate, sodium phosphate, cesium phosphate, zinc phosphate, etc .; phosphate compounds, phosphite compounds, phosphonite compounds, etc., but in the present invention, phosphorus-based As the agent (C), a phosphite stabilizer (C-I) represented by the following general formula (I) and / or a phosphite stabilizer (C-II) represented by the following general formula (II) use. By selecting such a phosphite compound, it is possible to obtain a polycarbonate resin composition for optical parts having high transparency and higher heat discoloration resistance.

In formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represent an alkyl group, an aryl group or an aralkyl group, and a to d Each independently represents an integer of 0 to 3;
Wherein ^{(II), R} 21 ~R ²⁵ represent each independently a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.

In the above general formula (I) of the phosphite stabilizer (C-I), R ^{11 to} R ¹⁸ are preferably each independently an alkyl group having 1 to 5 carbon atoms, and a methyl group, an ethyl group, A propyl group, n- or tert-butyl group is more preferable, and in particular, a methyl group is preferable, and a to d are preferably 0.

  The phosphite stabilizers (C-I) may be used alone or in combination of two or more.

As the phosphite stabilizer (C-I), bis (2,4-dicumylphenyl) pentaerythritol diphosphite represented by the following structural formula (Ia) is particularly preferable.

The alkyl group represented by R ^{21 to} R ²⁵ in the general formula (II) of the phosphite stabilizer (C-II) is preferably an alkyl group having a carbon number of 1 to 10, and examples thereof include a methyl group and an ethyl group Preferred are propyl, n-propyl, n-butyl, tert-butyl, hexyl and octyl.

  The above phosphite stabilizers (C-II) may be used alone or in combination of two or more.

As the phosphite stabilizer (C-II), in particular, (tris (2,4-di-tert-butylphenyl) phosphite represented by the following structural formula (IIa) is preferable.

  In the polycarbonate resin composition of the present invention, the combined use of a phosphite stabilizer (C-I) and a phosphite stabilizer (C-II) as the phosphorus stabilizer (C) also further improves the initial hue. It is preferable from the viewpoint of enhancing the heat discoloration resistance.

  The content of the phosphorus-based stabilizer (C), that is, the phosphite-based stabilizer (C-I) and / or the phosphite-based stabilizer (C-II) is 100 parts by mass of the polycarbonate resin (A), It is 0.005 to 0.5 parts by mass, more preferably 0.007 parts by mass or more, still more preferably 0.008 parts by mass or more, particularly preferably 0.01 parts by mass or more, and more preferably 0 .4 parts by mass or less, more preferably 0.3 parts by mass or less, in particular 0.2 parts by mass or less, particularly preferably 0.1 parts by mass or less. When the content is less than 0.005 parts by mass, the hue and the heat-resistant discoloration tend to be insufficient, and the initial hue is also likely to be inferior. If the content exceeds 0.5 parts by mass, the amount of gas during molding increases and transfer defects due to mold deposition occur, so the light transmittance of the resulting molded article tends to decrease, and heat-resistant discoloration occurs. On the contrary, the heat and humidity stability tends to deteriorate.

[Epoxy Compound (D) or Oxetane Compound (E)]
The polycarbonate resin composition of the present invention preferably also contains an epoxy compound (D) or an oxetane compound (E).

[Epoxy Compound (D)]
It is also preferable that the resin composition of the present invention contains an epoxy compound (D). By containing the epoxy compound (D) together with the polyalkylene glycol (B), the heat discoloration resistance can be further improved.

As the epoxy compound (D), a compound having one or more epoxy groups in one molecule is used. Specifically, phenyl glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl -3 ', 4'-Epoxy-6'-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-3', 4'-epoxycyclohexylcarboxylate, 4- (3,4-epoxy-5-methylcyclohexyl) Butyl-3 ', 4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6' -Methyl hexyl carboxylate, bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis- Epoxy ethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenyl ethylene epoxide, octyl epoxy tallow, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2 -Epoxycyclohexane, 3-methyl-5-t-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxy , N-butyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2-isopropyl-3,4-epoxy -5-Methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3 ', 4'-epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3', 4'-epoxycyclohexyl carboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5-epoxy tetrahydrophthalic anhydride, diethyl 4,5-epoxy-cis-1,2-cyclohexyldicarboxy Rate, di-n-b Le -3-t-butyl-4,5-epoxy - cis-1,2-cyclohexyl dicarboxylate, epoxidized soybean oil, can be preferably exemplified such as epoxidized linseed oil.
The epoxy compounds may be used alone or in combination of two or more.

  Among these, alicyclic epoxy compounds are preferably used, and in particular, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexyl carboxylate is preferable.

  The content of the epoxy compound (D) is preferably 0.0005 to 0.2 parts by mass, more preferably 0.001 parts by mass or more, still more preferably 0 based on 100 parts by mass of the polycarbonate resin (A). .003 parts by mass or more, particularly preferably 0.005 parts by mass or more, more preferably 0.15 parts by mass or less, still more preferably 0.1 parts by mass or less, particularly preferably 0.05 parts by mass or less . When the content of the epoxy compound (D) is less than 0.0005 parts by mass, the hue and the heat discoloration resistance tend to be insufficient, and when it exceeds 0.2 parts by mass, the heat discoloration resistance is easily deteriorated and the hue and Wet heat stability also tends to decrease.

[Oxetane Compound (E)]
It is also preferable that the resin composition of the present invention contains an oxetane compound (E). By containing the oxetane compound (E) in combination with the polyalkylene glycol (B), the heat discoloration resistance can be further improved.

As an oxetane compound, any compound can be used as long as it is a compound having one or more oxetane groups in the molecule, and a monooxetane compound having one oxetane group in the molecule and two or more oxetane groups in the molecule Any difunctional or higher functional polyoxetane compound can be used.
By containing the oxetane compound, it is possible to further improve the good hue and the high degree of thermal discoloration resistance.

  As a monooxetane compound, the compound etc. which are represented with the following general formula (III-a), (III-b) or (IV) can be illustrated preferably.

(Wherein, R ¹ represents an alkyl group, R ² represents an alkyl group or a phenyl group, R ³ represents a divalent organic group which may have an aromatic ring, and n represents 0 or 1)

In the above general formulas (III-a), (III-b) and (IV), R ¹ is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, preferably a methyl group or an ethyl group, Particularly preferred is an ethyl group.
R ² is an alkyl group or a phenyl group, preferably an alkyl group having 2 to 10 carbon atoms, and may be any of a chain alkyl group, a branched alkyl group and an alicyclic alkyl group. Alternatively, it may be a chain or branched alkyl group having an ether bond (ether type oxygen atom) in the middle of the alkyl chain. Specific examples of R ² include ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, 3-oxypentyl, cyclohexyl and phenyl Groups can be mentioned. Among them, R ² is preferably a ² -ethylhexyl group, a phenyl group or a cyclohexyl group.

Specific examples of the compound of the general formula (III-a) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyl oxetane, 3-hydroxymethyl-3-propyl oxetane, 3-hydroxymethyl- Preferred are 3-normal butyl oxetane, 3-hydroxymethyl-3-propyl oxetane and the like. Among them, 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyl oxetane and the like are particularly preferable.
As a specific example of the compound of the general formula (III-b), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane and the like are particularly preferable.

In the general formula (IV), R ³ is a divalent organic group which may have an aromatic ring, and examples thereof include ethylene group, propylene group, butylene group, neopentylene group and n-pentamethylene group And a linear or branched alkylene group having 1 to 12 carbon atoms such as n-hexamethylene group, a phenylene group, a formula: -CH ² -Ph-CH ² -or -CH ² -Ph-Ph-CH ^2- (Here, Ph represents a phenyl group), a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol Z residue, a cyclohexane dimethanol residue, a tricyclode Candimethanol residue etc. can be mentioned.

  As specific examples of the compound of the general formula (IV), bis (3-methyl-3-oxetanylmethyl) ether, bis (3-ethyl-3-oxetanylmethyl) ether, bis (3-propyl-3-oxetanylmethyl) ether Ether, bis (3-butyl-3-oxetanylmethyl) ether, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 3-ethyl-3 {[(3-ethyl oxetane-3-) 1) methoxy) methyl} oxetane, 4, 4'-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, 1,4-bis [(3-ethyl-3- oxetanyl) methoxymethyl] benzene etc. It can mention especially preferably.

  The oxetane compounds (E) may be used alone or in combination of two or more.

  The content of the oxetane compound (E) is preferably 0.005 to 0.2 parts by mass, more preferably 0.007 parts by mass or more, particularly preferably 0 based on 100 parts by mass of the polycarbonate resin (A). The content is 0.11 parts by mass or more, more preferably 0.15 parts by mass or less, still more preferably 0.1 parts by mass or less, and particularly preferably 0.05 parts by mass or less. When the content of the oxetane compound (E) is less than 0.005 parts by mass, the hue and the heat discoloration resistance tend to be insufficient, and when the content is more than 0.2 parts by mass, the heat discoloration resistance tends to deteriorate rather It is easy to generate gas at the time of molding.

  It is also preferable to contain both an epoxy compound (D) and an oxetane compound (E), and the total content in that case is 0.005 to 0. 0. with respect to 100 mass parts of polycarbonate resin (A). It is preferably 2 parts by mass.

[Additives, etc.]
The polycarbonate resin composition for an optical component according to the present invention may contain other additives than those described above, for example, antioxidants, mold release agents, UV absorbers, fluorescent brighteners, pigments, dyes, and other resins than polycarbonate resins. Additives can be included such as polymers, flame retardants, impact modifiers, antistatic agents, plasticizers, compatibilizers and the like. These additives may be used alone or in combination of two or more.
In addition, when it contains other resin other than polycarbonate resin (A), it is preferable to make the content into 20 mass parts or less with respect to 100 mass parts of polycarbonate resin component (A), and 10 mass parts or less are more preferable. More preferably, it is 5 parts by mass or less, particularly preferably 3 parts by mass or less.

[Method of producing polycarbonate resin composition for optical parts]
There is no restriction on the method for producing the polycarbonate resin composition for optical parts of the present invention, and a widely known method for producing a polycarbonate resin composition for optical parts can be widely adopted, and the polycarbonate resin (A) and the polyalkylene glycol (B) can be used For example, a Banbury mixer, a roll, a polymer and a phosphorus-based stabilizer (C), and other components to be blended if necessary, are premixed using various mixers such as, for example, a tumbler or a Henschel mixer. The method of melt-kneading with mixers, such as a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, and a kneader, is mentioned. The melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320 ° C.

[Optical parts]
The polycarbonate resin composition for optical parts of the present invention can manufacture optical parts by molding pellets obtained by pelletizing the polycarbonate resin composition for optical parts described above by various molding methods. Alternatively, the resin melt-kneaded by an extruder may be directly molded into an optical component without passing through pellets.

The polycarbonate resin composition for optical parts according to the present invention is excellent in fluidity, and excellent in transparency and heat-resistant discoloration, so even when it is a thin molded article, it has excellent appearance of molded articles free of white point foreign matter, transmittance and Since the hue can be compatible, it is suitably used to mold thin optical parts by injection molding. It is preferable to shape | mold by resin temperature higher than 260-300 degreeC which is a temperature generally applied to injection molding of polycarbonate resin generally at the time of injection molding, and the resin temperature of 305-380 degreeC is preferable. The resin temperature is more preferably 310 ° C. or more, further preferably 315 ° C. or more, particularly preferably 320 ° C. or more, and more preferably 370 ° C. or less. In the case of using the conventional polycarbonate resin composition for optical parts, there is also a problem that white point foreign matter is easily generated on the surface of the molded product when the resin temperature at the time of molding is raised to mold a thin molded product. However, by using the resin composition of the present invention, it is possible to produce a thin-walled molded article having a good appearance even in the above temperature range.
In addition, with resin temperature, when it is difficult to measure directly, it is grasped as barrel preset temperature.

  Here, the thin-walled molded article refers to a molded article having a plate-like portion having a thickness of usually 1 mm or less, preferably 0.8 mm or less, more preferably 0.6 mm or less. Here, the plate-like portion may be a flat plate or a curved plate, or may be a flat surface or may have irregularities or the like on the surface, and the cross section has an inclined surface. Or it may be a bowl-shaped cross section or the like.

Examples of optical components include parts of devices and appliances that directly or indirectly use light sources such as LEDs, organic EL, incandescent lamps, fluorescent lamps, and cathode tubes, and light guide plates and members for surface light emitters are typical. It is illustrated as a thing.
The light guide plate is for guiding the light of a light source such as an LED among liquid crystal backlight units, various display devices, and lighting devices, and the light introduced from the side surface or the back surface is usually provided on the front surface Diffuse by the asperity, and give out uniform light. The shape is usually flat and may or may not have asperities on the surface.
The formation of the light guide plate is usually performed preferably by an injection molding method, a super high speed injection molding method, an injection compression molding method, or the like.
The light guide plate molded using the resin composition of the present invention has neither white turbidity nor a decrease in transmittance, and the transmittance and the hue are extremely good.

  The light guide plate using the polycarbonate resin composition for optical parts of the present invention can be suitably used in the field of liquid crystal backlight units, various display devices, and lighting devices. Examples of such devices include mobile phones, mobile notebooks, netbooks, slate PCs, tablet PCs, smartphones, various types of portable terminals such as tablet terminals, cameras, watches, notebook computers, various displays, lighting devices, etc. Be

  Hereinafter, the present invention will be more specifically described with reference to examples. However, the present invention is not construed as being limited to the following examples.

  Raw materials and evaluation methods used in the following examples and comparative examples are as follows. In addition, the measuring method of the viscosity average molecular weight of polycarbonate resin (A) is as having mentioned above.

(Examples 1 to 17, Comparative Example 1)
[Production of Resin Composition Pellets]
The components described above are compounded in proportions (parts by mass) described in Table 2 and Table 3 below, mixed with a tumbler for 20 minutes, and then a vented single-screw extruder with a screw diameter of 40 mm (manufactured by Tanabe Plastic Machinery Co., Ltd. According to “VS-40”, melt kneading was performed at a cylinder temperature of 250 ° C. and 100 rpm, and pellets of the polycarbonate resin composition were obtained by strand cutting.
In each polycarbonate resin composition, tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) with respect to the entire (100 mol%) of polyalkylene glycol (B) compounded The proportion (mol%) of is shown in Table 2.

[Hue (YI)]
The resulting pellets are dried at 120 ° C. for 5 to 7 hours with a hot air circulating drier, and then a resin temperature of 340 ° C., a mold temperature of 80 ° C., and a cycle of 40 seconds by an injection molding machine (“HSP100A” manufactured by Sodick Co., Ltd. Thus, a long optical path molded product (300 mm × 7 mm × 4 mm) was molded.
The long-path molded product was measured for YI (degree of yellowing, based on ASTM D1925) at a light path length of 300 mm. For measurement, a long path spectral transmission colorimeter (“ASA 1” manufactured by Nippon Denshoku Kogyo Co., Ltd., C light source, 2 ° visual field) was used.

[ΔYI: Evaluation of heat discoloration resistance]
Moreover, YI after hold | maintaining the said long-path-pass molded goods at 95 degreeC for 500 hours was measured, the difference (DELTA) YI of YI value was calculated | required, and heat-resistant discoloration was evaluated. As the ΔYI is smaller, the heat discoloration resistance is more excellent.
The above evaluation results are shown in Tables 2 and 3 below.

  The polycarbonate resin composition for an optical component according to the present invention is excellent in transparency and heat-resistant discoloration, so that it can be particularly suitably used for an optical component, and its industrial applicability is very high.

Claims (9)

It is a resin composition which contains 0.1 to 4 parts by mass of polyalkylene glycol (B) and 0.005 to 0.5 parts by mass of phosphorus stabilizer (C) with respect to 100 parts by mass of polycarbonate resin (A). ,
A copolymer component in which polyalkylene glycol (B) is copolymerized with at least two or more units selected from tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) Including
A phosphite stabilizer (C-I) represented by the following general formula (I) and / or a phosphite stabilizer (C-) represented by the following general formula (II) Polycarbonate resin composition for optical parts characterized by including II).
(In formula (I), R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group, R ^{19 to} R ²² each independently represent an alkyl group, an aryl group or an aralkyl group, and a to d respectively independently shows the integer of 0-3.)
(In formula (II), R ^{21 to} R ²⁵ each independently represent a hydrogen atom, an aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.   The copolymer according to claim 1, wherein the (2-methyl) ethylene glycol unit (b2) and / or the ethylene glycol unit (b3) in the polyalkylene glycol (B) is copolymerized with the tetramethylene glycol unit (b1). The polycarbonate resin composition for optical components as described.   The copolymer according to claim 1 or 2, wherein the (2-methyl) ethylene glycol unit (b2) and the ethylene glycol unit (b3) in the polyalkylene glycol (B) are copolymerized with the tetramethylene glycol unit (b1). The polycarbonate resin composition for optical components as described. Polyalkylene glycol (B) is
(I) A copolymer having tetramethylene glycol unit (b1) and (2-methyl) ethylene glycol unit (b2),
(Ii) Copolymer having tetramethylene glycol unit (b1) and ethylene glycol unit (b3), or (iii) Copolymer having (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3) Or a combination of two or more copolymers selected from
(Iv) The copolymer is contained as a copolymer having tetramethylene glycol unit (b1), (2-methyl) ethylene glycol unit (b2) and ethylene glycol unit (b3). The polycarbonate resin composition for optical parts as described in.   The polyalkylene glycol (B) is contained by using the copolymer of (i) and the copolymer of (ii) in combination, or is contained as a copolymer of (iv). Polycarbonate resin composition for optical parts as described in 4. The aromatic polycarbonate resin composition according to any one of claims 1 to 5, wherein the phosphite stabilizer (C-I) is a compound represented by the following structural formula (Ia).
  The polycarbonate resin composition for optical parts according to any one of claims 1 to 6, wherein the number average molecular weight of the polyalkylene glycol (B) is more than 1,200 to less than 5,000.   The polycarbonate resin composition according to any one of claims 1 to 7, further comprising an epoxy compound (D) or an oxetane compound (E).   The optical component which shape | molded the polycarbonate resin composition in any one of Claims 1-8.